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Sept. 24 (UPI) -- NASA: Antarctica snowmelt moving inland BALTIMORE, Sept. 24 (UPI) -- NASA scientists studying 20 years of data from space-based sensors found Antarctic snow is increasingly melting farther inland and at higher altitudes.

The discovery is significant, scientists said, since Antarctica contains 90 percent of Earth's fresh water, making it the largest potential source of sea level rise. It is also a place where snow melting is limited because, even in summer, most areas typically record temperatures well below zero.

National Aeronautics and Space Administration scientists using data collected from 1987 to 2006 found snow is now melting as far inland as 500 miles from the Antarctic coast and as high as 1.2 miles above sea level in the Transantarctic Mountains.

The data also confirm melting has increased on the Ross Ice Shelf, both in geographic area and in duration.

"Snow melting is very connected to surface temperature change, so it's likely warmer temperatures are at the root of what we've observed in Antarctica," said lead author Marco Tedesco, a research scientist at the Joint Center for Earth Systems Technology cooperatively managed by NASA's Goddard Space Flight Center and the University of Maryland.

The study appears in the current issue of Geophysical Research Letters.

Organ size may be linked with cancer BALTIMORE, Sept. 24 (UPI) -- U.S. scientists have discovered a chemical chain reaction that controls animals' organ size might also control cancer.

"This chain reaction, a domino-like chain of events we call the Hippo pathway, adds a single chemical group on a protein nicknamed Yap," said Johns Hopkins University Associate Professor Duojia Pan.

"The good news is that maybe all organ growth can be reduced to this one chemical event on the Yap protein," said Pan. "But the better news is that we potentially have a new target for cancer therapy."

Pan and colleagues previously discovered in fruit flies that too much Yap supercharges growth-inducing genes and causes organs to overgrow. In the new study designed to see if the same effect occurred in mammals, the research team genetically altered mice to make high levels of Yap protein but only in liver cells.

Those animals' livers grew to be five times the size of a normal mouse liver and often were dotted with large tumors. "We were totally amazed," said Pan. "We think it might be the extra Yap in these cells contributing to their cancerous growth."

The study is detailed in the journal Cell.

Scientists model possible planets GREENBELT, Md., Sept. 24 (UPI) -- U.S. scientists have developed a model of Earth-size planets that astronomers might discover in the near future.

The researchers created models for 14 different types of solid planets that might exist in our galaxy. The 14 types have various compositions and the team calculated how large each planet would be for a given mass. Some are pure water ice, carbon, iron, silicate, carbon monoxide and silicon carbide; while others are mixtures of various compounds.

"We're thinking seriously about the different kinds of roughly Earth-size planets that might be out there, like George Lucas, but for real," said Marc Kuchner of NASA's Goddard Space Flight Center.

The team took a different approach from previous studies. Rather than assume planets around other stars are versions of the planets in our solar system, they considered all types of planets that might be possible, given what astronomers know about the composition of protoplanetary disks around young stars.

The research that included Kuchner, Sara Seager of the Massachusetts Institute of Technology, the late Catherine Hier-Majumder of the Carnegie Institution of Washington, and Burkhard Militzer of Carnegie is to be reported in the Oct. 20 issue of the Astrophysical Journal.

Potential new drug found for schizophrenia PITTSBURGH, Sept. 24 (UPI) -- U.S. researchers have developed a drug that promises to treat the cognitive deficits associated with schizophrenia.

The scientists said the hallucinations, delusions and emotional deficits that are features of schizophrenia can be treated by existing medicines. However, they said those medicines have limited effects on the impaired attention, memory and problem-solving that comprise the cognitive deficits of schizophrenia.

University of Pittsburgh Professor Bita Moghaddam and colleagues at the Institute for Neurodegenerative Disorders in New Haven, Conn., investigated various compounds that affect brain cells in the prefrontal cortex and hippocampus by using the chemical glutamate as a neurotransmitter.

They succeeded in identifying a specific drug that affects glutamate receptors and reverses chemically induced abnormalities in prefrontal cortical functioning.

Moghaddam said the drug "has a normalizing effect on the spontaneous activity of prefrontal cortex neurons" and the work might lead to development of drugs designed to selectively treat the cognitive deficits of schizophrenia.

The research is to be published in the journal Biological Psychiatry.

Copyright 2007 by United Press International

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